The present invention relates to a binocular, and more particularly, to a binocular including telescope optical systems that each include an erecting prism for erecting images.
Conventionally, a binocular includes two telescope systems, left and right. Each telescope system has, respectively, (at least) an objective lens, an erecting prism for erecting an inverse image that is imaged by the objective lens, and an eyepiece lens for observing the erected image.
In each telescope optical system, the erecting prism may be adjustable along the vertical and lateral directions with respect to an optical axis of the telescope optical system, so that the erected image, to be seen through the eyepiece optical lens, is formed inside a field stop, with a predetermined acceptable play. If the telescope optical system is a zoom system, the acceptable play takes into account various magnifying powers of the telescope optical system.
In particular, when a holder for holding the erected prism is installed in an attachment member, the location of the holding member with respect to the attachment member is adjusted so that the location of the erecting prism with respect to the optical axis can be adjusted properly.
In the conventional binocular, however, no particular adjustment structure or mechanism is provided, and such adjustment is made by means of inserted members that are difficult to arrange, such as shims, spacers, etc. That is, no adjustable structure or mechanism that is part of the binocular is provided, so that the adjustment of the erecting prism is both time-consuming and requires a high level of necessary skills. These drawbacks cause low productivity in manufacturing or repair.
Furthermore, in the conventional binocular, the location of the erecting prism with respect to the optical axis should be adjusted at the time of installation of the erecting prism to the attachment member, i.e., in the assembly stage. Therefore, when the location of the erecting prism requires later adjustment (e.g., due to independent reasons after the binocular is assembled, such correction of misalignment, or other repair or optimizing tasks), numerous parts other than the holding member and attachment member must be demounted in order to carry out the adjustment.
Still further, if the location of the erecting prism must be adjusted after the binocular has been assembled, any outer member covering the binocular must be removed so that the holding member and the attachment member can be adjusted as noted above, which also requires extra time and expense.
It is therefore an object of the invention to provide a binocular in which the erecting prism location can be adjusted easily and precisely, enhancing the efficiency of the adjustment process (including before or after shipment).
According to one aspect of the present invention, a binocular includes a right telescope system and a left telescope optical system. Each of the telescope optical systems includes an objective lens, a roof prism that forms an erected image, and an eyepiece lens for observing the erected image. An optical adjustment structure adjusts a location of the roof prism in a first direction and a second direction. The first direction and the second direction are perpendicular to optical axes of the telescope optical systems and perpendicular to one other.
Optionally, the optical arrangement structure includes a prism holder, an intermediate member, and a holding member. The prism holder is configured to hold the roof prism. The intermediate member is configured to support the prism holder to be movable in the first direction but prevented from movement in the second direction, and the holding member is configured to support the intermediate member to be movable in the second direction but prevented from movement in the first direction.
In such a case, the intermediate member may include a first guiding member and the prism holder may include a first guided member. One of the first guiding member and the first guided member extends in the first direction, the first guided member of the prism holder being guided in the first direction by the first guiding member of the intermediate member.
Alternatively or in addition, the holding member may include a second guiding member and the intermediate member may include a second guided member. One of the second guiding member and the second guided member extends in the second direction, the second guided member of the intermediate member being guided in the second direction by the second guiding member of the holding member.
The intermediate member may include a first plate-like portion formed on a surface opposing the prism holder, the first plate-like portion being plate shaped and having a first substantially circular hole formed therein. In this case, the prism holder includes a first long groove elongated in the second direction and opposing the first substantially circular hole. The first hole and the first long groove may be arranged with respect to each other in relative positions in which the first hole receives a cylindrical body of a first arrangement member, and the first long groove receives an eccentric shaft portion of the first arrangement member that extends from an end of the cylindrical body and is eccentric with respect to an axis of rotation of the cylindrical body.
As to the first long groove, two side edges of the first long groove that oppose each other in an elongation direction of the first long groove may abut an outer circumferential surface of the eccentric shaft portion of the first arrangement member when the prism holder is moved in the first direction with respect to the intermediate member upon rotation of the first arrangement member.
The holding member may alternatively or also include a second plate-like portion formed on a surface opposing the intermediate member, the second plate-like portion being plate shaped and having a second substantially circular hole formed therein. The intermediate member then includes a second long groove elongated in the first direction and opposing the substantially circular second hole. The second hole and the second long groove may be arranged with respect to each other in relative positions in which the second hole receives a cylindrical body of a second arrangement member, and the second long groove receives an eccentric shaft portion of the second arrangement member that extends from an end of the cylindrical body and is eccentric with respect to an axis of rotation of the cylindrical body. Two side edges of the second long groove that oppose each other in an elongation direction of the second long groove may abut an outer circumferential surface of the eccentric shaft portion of the second arrangement member. In this case, the intermediate member is moved in the second direction with respect to the holding member upon rotation of the second arrangement member.
According to another aspect of the present invention, a binocular includes right and left telescope optical systems. Each of the right and left telescope optical systems includes an objective lens, an erecting prism that forms an erected image, and an eyepiece lens for imaging the erected image. An optical axis is defined by the objective lens, the erecting prism, and the eyepiece lens. A prism holding structure adjusts a location of the erecting prism in a first direction and a second direction. The first direction and the second direction are perpendicular to optical axes of the telescope optical system and perpendicular to one another. A prism location arrangement structure moves the location of the erecting prism within the prism holding structure, and is adapted to receive an arrangement jig and move the location of the erecting prism within the prism holding structure according to a rotational operation of the arrangement jig. Optionally, a shaft reception member may be provided for rotatably supporting the arrangement jig while the arrangement jig is rotated.
Optionally, the prism holding structure may include a prism holder, an intermediate member, and a holding member. The prism holder is configured to hold the erecting prism, the intermediate member is configured to support the prism holder to be movable in the first direction but prevented from movement in the second direction, and the holding member is configured to support the intermediate member to be movable in the second direction but prevented from movement in the first direction.
In addition or alternatively, the intermediate member may include a first guiding member and the prism holder may include a first guided member. One of the first guiding member and the first guided member extends in the first direction, the first guided member of the prism holder being guided in the first direction by the first guiding member of the intermediate member. The holding member includes a second guiding member and the intermediate member includes a second guided member. One of the second guiding member and the second guided member extends in the second direction, the second guided member of the intermediate member being guided in the second direction by the second guiding member of the holding member.
Further, the intermediate member may include a first plate-like portion formed on a surface opposing the prism holder, the first plate-like port ion being plate shaped and having a first substantially circular hole formed therein. In this case, the prism holder includes a first long groove elongated in the second direction and opposing the first substantially circular hole.
The holding member may have a second plate-like portion formed on a surface opposing the intermediate member, the second plate-like portion being plate shaped and having a second substantially circular hole formed therein. The intermediate member may include a second long groove elongated in the first direction and opposing the substantially circular second hole.
As to the first hole and the first long groove, they may be arranged with respect to each other in relative positions in which the first hole receives a cylindrical body of the arrangement jig and the first long groove receives an eccentric shaft portion of the arrangement jig that extends from an end of the cylindrical body and is eccentric with respect to an axis of rotation of the cylindrical body. Two side edges of the first long groove that oppose each other in an elongation direction of the first long groove may abut an outer circumferential surface of the eccentric shaft portion.
As to the second hole and the second long groove, they may be arranged with respect to each other in relative positions in which the second hole receives a cylindrical body of the arrangement jig and the second long groove receives an eccentric shaft portion of the arrangement jig that extends from an end of the cylindrical body and is eccentric with respect to an axis of rotation of the cylindrical body. Two side edges of the second long groove that oppose each other in an elongation direction of the second long groove may abut an outer circumferential surface of the eccentric shaft portion.
The shaft reception member may include a plate-like portion, a jig insertion hole formed in the plate-like portion for receiving the arrangement jig, and an arch portion formed on a portion of a hole edge of the jig insertion hole, the arch portion forming an arched edge expanding outward from a center of the jig insertion hole. The diameter of the arch portion is optionally less than the half of that of the jig insertion hole, the arrangement jig is being received and rotatably supported by the arch portion.
The binocular may further include one or more outer housing members formed to house the binocular. The prism location arrangement structure engages with the arrangement jig at an engaging interface, and the engaging interface of the prism location arrangement structure is covered from an exterior of the binocular by the outer housing member.
In this case, the outer housing member may include an eyepiece, the eyepiece being removably attached to the binocular at the eyepiece lens.